The earth's atmosphere is not only essential for breathing, but important among its many functions is the ability to trap the sun's heat or solar energy.
To prevent over heating there is a natural "atmosphere to space" window through which some heat escapes into space under clear skies.
It is this natural heat-release window in the earth's greenhouse which SkyCool uses to radiate a large portion of its heat directly into space. In bypassing the heating of the nearby atmosphere it acts like a "passive heat pump" removing heat from hot buildings day and night.
As the University of Technology, Sydney (UTS) discovered:
"SkyCool has been proven by our tests to be generally capable of eliminating those heat gains through a roof associated with the heating of the roof by the incident solar radiation. Such gains dominate the heat inflow from traditional metal roofs even with batt type insulation installed.
"It achieves this by a combination of two properties, high solar reflectance and high thermal emittance, which we have verified by direct measurement."
Please review the Technology reports for further details on the findings of several universities.